According to a 2007 World Health Organization report, over one billion people around the globe lack access to a purified water supply. That means they treat water by boiling with firewood--which increases greenhouse gas emissions.
That could soon change. WWF announced that it chose Solvatten, a solar-powered water purifier, as a "climate solver." The WWF estimates that devices like this, with widespread distribution, could reduce CO2 emissions by as much as 26 million tons per year by the year 2020.
The Solvatten reduces dependence on firewood and other fossil fuels, as it uses the sun's rays to treat water and also heats it--meaning that it also saves on energy when cooking, bathing, and washing dishes. It takes about two to six hours to make 10 liters of water drinkable, and contains an indicator to show when it's ready.